A typical gas turbine that is used to generate electrical power includes an axial compressor, one or more combustors downstream from the compressor, and a turbine that is downstream from the combustors. Ambient air is supplied to the compressor, and rotating blades and stationary vanes in the compressor progressively impart kinetic energy to the working fluid (air) to produce a compressed working fluid at a highly energized state. The compressed working fluid exits the compressor and flows towards a head end of combustor where it reverses direction at an end cover and flows through the one or more fuel nozzles into a primary combustion zone that is defined within a combustion chamber in each combustor. The compressed working fluid mixes with fuel in the one or more fuel nozzles and/or within the combustion chamber and ignites to generate combustion gases having a high temperature and pressure. The combustion gases expand in the turbine to produce work. For example, expansion of the combustion gases in the turbine may rotate a shaft connected to a generator to produce electricity.
A typical combustor includes an end cover that is coupled to a first outer casing such as a compressor discharge casing, at least one axially extending fuel nozzle that extends downstream from the end cover, and an annular cap assembly that extends radially and axially within the compressor discharge casing. Some combustor designs may include a forward case disposed between the end cover and the compressor discharge casing. A particular combustor includes a combustion module for providing late lean fuel injection to the combustor. The combustion module generally includes a fuel distribution manifold that circumferentially surrounds at least a portion of the cap assembly, and a fuel injection assembly that extends downstream from the fuel distribution manifold and that terminates at a point that is upstream from a first stage of stationary nozzles. When mounted within the combustor, a forward end of the fuel distribution manifold is coupled to the first outer casing.
The fuel injection assembly generally includes a combustion liner, a flow sleeve that circumferentially surrounds at least a portion of the combustion liner, an aft frame that is disposed at an aft end of the fuel injection assembly, and a plurality of fuel injectors that extend through the flow sleeve and the combustion liner. When mounted within the combustor, the aft frame is connected to a second outer casing such as an outer turbine casing and/or to a turbine nozzle retaining ring. A plurality of fluid conduits provide for fluid communication between the fuel distribution manifold and each of the plurality of fuel injectors. One end of each fluid conduit is connected to the fuel distribution manifold and a second end of each fluid conduit is connected to a corresponding one of the plurality of fuel injectors.
Assembly of the combustion module in situ on the gas turbine is challenging for various reasons. For example, limited access to the combustion module in situ on the gas turbine, in particular access to the connections between the fluid conduits and the fuel distribution manifold and/or the fuel injector, can make assembly difficult. In addition, the limited access generally restricts a technician's ability to visually inspect the connection between each fluid conduit and the fuel distribution manifold and/or the fuel injector, thereby resulting in increased man hours to complete the inspection. Therefore, a support frame which allows for assembly and testing of the combustion module prior to installation into the gas turbine would be useful.